//给你二叉树的根节点 root 和一个整数目标和 targetSum ，找出所有 从根节点到叶子节点 路径总和等于给定目标和的路径。 
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// 叶子节点 是指没有子节点的节点。 
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// 示例 1： 
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//输入：root = [5,4,8,11,null,13,4,7,2,null,null,5,1], targetSum = 22
//输出：[[5,4,11,2],[5,8,4,5]]
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// 示例 2： 
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//输入：root = [1,2,3], targetSum = 5
//输出：[]
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// 示例 3： 
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//输入：root = [1,2], targetSum = 0
//输出：[]
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// 提示： 
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// 树中节点总数在范围 [0, 5000] 内 
// -1000 <= Node.val <= 1000 
// -1000 <= targetSum <= 1000 
// 
//
// Related Topics 树 深度优先搜索 回溯 二叉树 👍 982 👎 0

package leetcode.editor.cn;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.LinkedList;
import java.util.List;

//java:路径总和 II
public class Q0113PathSumIi {
    public static void main(String[] args){
//        Solution solution = new Q0113PathSumIi().new Solution();
        TreeNode root = new TreeNode(5);
        root.left = new TreeNode(4);
        root.right = new TreeNode(8);
        root.left.left = new TreeNode(11);
        root.left.left.left = new TreeNode(7);
        root.left.left.right = new TreeNode(2);
        root.right.left = new TreeNode(13);
        root.right.right = new TreeNode(4);
        root.right.right.left = new TreeNode(5);
        root.right.right.right = new TreeNode(1);
        List<List<Integer>> res = new Q0113PathSumIi().new Solution().pathSum(root, 22);
        System.out.println(Arrays.toString(res.toArray()));
    }
    //leetcode submit region begin(Prohibit modification and deletion)
/**
 * Definition for a binary tree node.
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode() {}
 *     TreeNode(int val) { this.val = val; }
 *     TreeNode(int val, TreeNode left, TreeNode right) {
 *         this.val = val;
 *         this.left = left;
 *         this.right = right;
 *     }
 * }
 */
class Solution {
    List<Integer> curList = new ArrayList<>();
    List<List<Integer>> resList = new ArrayList<>();

    public List<List<Integer>> pathSum(TreeNode root, int targetSum) {
        if (root == null) return null;
        dfs(root, targetSum);
        return resList;
    }

    public void dfs(TreeNode root, int sum) {
        if (root == null) return;
        int tar = sum - root.val;
        curList.add(root.val);
        if (tar == 0 && root.left == null && root.right == null) {
            resList.add(new ArrayList<>(curList));
        }

        if (root.left != null) dfs(root.left, sum - root.val);
        if (root.right != null) dfs(root.right, sum - root.val);
        curList.remove(curList.size() - 1);
    }

}
//leetcode submit region end(Prohibit modification and deletion)

}